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Ansys LS-DYNA 2023 R1 Update Presentation – What’s New!

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Community

How to output XY data in Fringe Plot
Hello, I'm using the SPH method to simulate a high-speed ballistic impact problem. I want to output the strain energy of the individual particle. I cannot find the strain energy icon in the #History in LS-Prepost, but I find it in the Fringe Component.I can only display the contours of the strain energy, but I don't know how to output these values as XY pairs.Could you show me the steps in detail? Best,Rong
Avatar
Rong Jin March 18, 2024
Error 20227
I'm preparing model in  ls-dyna for seatbelt analysis. When I try to run a calculation, an error occures. Weird, because there are no beam elements with those id.Thanks for help.
Avatar
michal March 17, 2024
contact between two perpendicular shell plates
Hi, I am using shell elements for an I section and applying blast loading on its weak axis. I couldnt able to establish proper contact between flange and web. Any suggestions which contact is more suitable!  I tried merging nodes but couldnt achieve good results
Avatar
Jaswanth Gangolu March 17, 2024
Running more simulations at a time and extract results without manually opening
Hi, I need to automate running simulations and extracting results without manually opening each simulation. I'm using LS-DYNA to model blast loading on steel columns. Can someone provide a solution for this, preferably using MATLAB?
Avatar
Jaswanth Gangolu March 17, 2024
Ogden material models are used to show anomalies in LS-DYNA
Hello everyone, I got the stress-strain curve of uniaxial compression test of a foam, and used it to build its Ogden material model in the engineering database, as shown in the figure. I used the fitting function of ANSYS to get the parameters of the material formula. When I used it for Droptest emulation, the solver gave me an error and I couldn't figure out why. In addition, I found a rubber 1 material in the engineering database, but it can normally participate in calculation. I couldn't find the reason for my calculation failure. I hope you can help me if you are in the same situation as me, thank you 
Avatar
云川 王 March 16, 2024
How autodyn imports external energy deposition
Hello, I have a question about autodyn. I would like to ask you how autodyn imports external energy deposition. I built a copper cylinder, and then knew the energy deposition corresponding to each point in it. How can I introduce the energy deposition into the cylinder, and then calculate the density pressure after a certain time, etc. I tried to carry out secondary development of autodyn and found that the EXSIE module in the subroutine can import energy deposition, but it only has one input parameter. I don't know how to input it, so I would like to ask for advice. The picture shows the subroutine EXSIEThe picture shows the energy deposition I want to import. The first and second columns are the coordinates, and the third column is the corresponding energy deposition
Avatar
wei zhang March 14, 2024
*DATABASE_TRHIST activation
I want to use the database *DATABASE_TRACER, but the R13 and R14 manuals state, "The option *DATABASE_TRHIST must be active." I can't find how to make it active in the manuals. Can anyone shed light on this? 
Avatar
Sa-aadat Parker March 14, 2024
About the energy plot in LS-DYNA
Hello,I'm using the SPH method in LS-DYNA to simulate the high-speed impact problem (Using a metal ballistic projectile to impact a metal plate). I find that the internal energy is not consistent with different numbers of particles (different meshes) for the plate and the projectile. The results are listed below, which are the coarse mesh (70*70*19=93100 nodes), medium mesh (107*107*28=320572 nodes), and fine mesh (151*151*40=912040 nodes).All the other setups are kept the same for the three cases. As can be seen, the internal energy is not convergent for these cases. For example, the internal energy at 1e-5 s is 2.8e9 (coarse mesh), 3e9 (medium mesh), and 3.5e9 (fine mesh) respectively. These results are calculated by the R 13.0 solver. I also tried to use R 14.0 solver but the results still show a different trend. Even for some cases, the job will stuck at 33% or 46% and I don't know why.I would like to know how LS-DYNA calculates the internal energy and how I can verify it. We know that the internal energy can be divided into two parts. One is the strain energy, which can be calculated by particle strain and stress. The other is heat, which can be calculated by the particle temperature change. For strain energy, I plan to output all the stress and strain of all the particles in each timestep, then I can calculate the increment of strain δε, then time σ, and the total volume and sum, which is the internal energy. For the heat, I plan to output all the temperature change, then times the total mass and specific heat capacity, which is the total heat generated. However, in some cases, I find that the sum of total strain energy calculated and total heat calculated does not equal to the total internal energy directly plotted in *MATSUM. Best,Rong
Avatar
Rong Jin March 13, 2024
A question about the Stiffness Type in Coupling
Dear all,I am using LS-DYNA to simulate a bottle filled with water falling onto the ground. When setting up the Coupling, I chose "Tabular" for the Stiffness Type. Therefore, I need to input Displacement vs. Coupling Pressure. Can anyone tell me what the values (The displacement vs pressure) should be like for my simulation case? Best,Tomas
Avatar
Tomas Black March 13, 2024
Cylindrical Coordinate System
Can I please know how to provide the cylindrical coordinate system (rotation, theta and z) for providing BOUNDARY_SPC in LS DYNA?
Avatar
Thamanna Iqbal March 12, 2024
LS-OPT Error
Hello everyone,I'm a beginner in LS-OPT and I'm trying to practice on training examples. But every time I run a job, I get the same error message "No backtrace information avaible under windows". I've seen various solutions (no blank, or - in the main file...) on other forums, but none have helped. Do you have any idea what the problem is? I'm trying to identify a parameter with an LS-DYNA solver, something realy classic.Thanks 
Avatar
Pierre Gardère March 12, 2024
Mat 011 Steinberg Guinan translation to LS-DYNA keycard
Hello all, I posted previously about the Steinberg-Guinan model and implementing it in Workbench LS-DYNA as a keycard input. I have since attempted this but the formatting for the actual equation parameters is confusing, particularly the derivative terms. They are not well labeled in the LS-DYNA theory manual. Does anyone have an example material for Mat 011 in keycard format that I can compare to? Thank you!
Avatar
Alex Horwege March 12, 2024
SPH brittle modeling with UMAT
Greetings, dear colleagues. I want to perform the modeling of complex brittle failure of material with spalling. Could you please clarify the following points:1) I think about using the SPH method for this purpose but I heard that it is unstable for brittle crushing simulations. Is it true?2) Can I use my own material model (UMAT) with failure criterion for SPH simulations?3) Is it possible to define particle-to-particle contact between failed particles? I want to implement the case where crushed parts of model interact with each other after crushing. Thank you in advance.
Avatar
Oleg Makarov March 11, 2024
Write Input file Explicit Dynamic
Hello, how can i generate a Input file for a hpc server. I already tried to add a transient calculation to the explicit dynamics but it still doesn't work.Daniel
Avatar
Daniel Dabic March 11, 2024
About load setting
I want to use force to simulate a rotating object. How can I apply node forces in the normal direction of multiple nodes in ls-dyna?
Avatar
REX LIOU March 11, 2024
Connecting beam elements to solid elements
Hi,What is the best way to connect a beam element to a solid element in LS-prepost so that moments, shears and rotations are transfered at the interface? I am modelling a concrete pier that is connected to a concrete footing. The dynamic analysis is intended to remain within the linear elastic regime. I have modeled the pier with beam elements and the footing with brick (solid) elements. The pier is located at the center of the footing where there is no node at the top of the footing for direct connection, due to the mesh size and layout. I have tried using Constrained_Nodal_Rigid_Body to connect all the nodes at the top of the footing to the node at the bottom of the pier. The  results obtained were not realistic, thus, I am wondering if there is another way to make this connection in LS-prepost.Thanks
Avatar
king79 March 11, 2024
effetive stress vs strain curve not as expected
HiI used "MAT_PLASTIC_KINEMATIC model to model a pipe-tank simulation. The Mat card looks like below:I am applying 0.305 m displacement in +Y direction to represent sliding which looks like below: However, when I checked the effective stress at pipe-tank connection nodes, it seems they are not behaving as expected. I checked effective strain at a certain element which has maximum effective stress (at connection between tank and bottom), it looks like below: My yield stress was 450 MPa and E = 200 GPa. My yield strain is 0.092. So, @0.092 the stress should be 450 MPa, right? Do you know, why the stress-strain does not look okay? To let you know, I was applying prescribed motion by selecting all bottom nodes of tank in Y direction. But in other case, when I apply prescribed motion in Z direction to represent flotation of tank, I get expected results which looks below:
Avatar
mmia1@lsu.edu March 9, 2024
Warning 30064 (INI+64) material 140 is not included for silent boundaries
How to slove the "Warning 30064 (INI+64) material 140 is not included for silent boundaries"?I use the keyword  "BOUNDARY_SALE_MESH_FACE" to set the no reflective boundaries. When I run the program, "Warning 30064 (INI+64) material 140 is not included for silent boundaries" appears.How can I slove this problem?
Avatar
TAI Tim March 9, 2024
Deflections not matching for simple cantilever beam check
Hello,I am looking to use *ELEMENT_SHELL_COMPOSITE for tow-steered composite modeling and ran a simple cantilever beam test to see if the element type was working as expected.  For my test case, the material is steel (E = 200 GPa), the dimensions are L = 100 mm, w = 10 mm, and h = 3 mm, and a 50 N load is applied the the nodes at the end.  Solving by hand, I expect to get a deflection of about 3.7 mm.  I modeled the problem using *ELEMENT_SHELL and got 3.67 mm.  With the working model, I transfered the elements from *ELEMENT_SHELL to *ELEMENT_SHELL_COMPOSITE and modeled it with 3 "steel plies" each 1 mm thick.  The transfer was done by using EleTol->ElmEdit->Composite, inserting 3 plies, and assigning the material and thickness (I did not touch the direction).  Running this gave a deflection of 4.13 mm.  Any idea how to fix the *ELEMENT_SHELL_COMPOSITE model?  I did try LAMSHT=1 in *CONTROL_SHELL, but the deflection did not change.
Avatar
Eli Bogetti March 8, 2024
Cannot see material failure in simulation
Hello,I am trying to simulate a projectile impact onto a plate in LS-DYNA, and have been using the Johnson-Cook criteria for failure. However, when I run the simulation, it does not show fracture or damage the way I would expect. Instead, it simply stretched the plate. Is there a parameter that I might have missed?The materials selected for the plate are aluminum and titanium.Thank you. 
Avatar
Joshua Monsey March 7, 2024
error 3 in em_eleTypeToFemMapGlobBath1
I encountered an error while running the battery extrusion simulation, but I can't figure out where the problem is.May I ask where exactly this error occurred?
Avatar
LIN JUN HONG March 7, 2024
LS DYNA Tools
For my project, I need to providing stitching upon overlapped membrane parts (similarly like stitching of fabric material). Can I please know how to simulate this in LS DYNA?
Avatar
Thamanna Iqbal March 6, 2024
Calculating contact stiffness
Hello,I'm currently working on a thesis project and I'm trying to approximate a contact stiffness in order to compare the results of my simulation to those from a self written MATLAB routine in which I specify a contact stiffness as a concrete value. I'm using shells and what I can find is k = alpha*K*A / (max shell diagonal) where k is the contact stiffness, alpha is a penalty scale factor, K is the bulk modulus and A is the segment area.Assuming this is the right way to calculate it and provided I use a mesh with equally sized elements (that is, I know the max shell diagonal), how do I find alpha and A? The contact I'm looking at is a turbine blade edge coming into contact with the surrounding stator wall surface.Thanks in advance for the help.
Avatar
Henrik Wittberg March 6, 2024
Do I need to set both surface contact and body interaction in workbench LS-DYNA?
Dear all,If we have already set the surface bonded contact between two parts, do I still need to set the solid interaction between them? I find that whether or not the solid interaction is set, the results obtained from the calculations can be different.Thanks,Tomas
Avatar
Tomas Black March 6, 2024
How to output XY data in Fringe Plot
Hello, I'm using the SPH method to simulate a high-speed ballistic impact problem. I want to output the strain energy of the individual particle. I cannot find the strain energy icon in the #History in LS-Prepost, but I find it in the Fringe Component.I can only display the contours of the strain energy, but I don't know how to output these values as XY pairs.Could you show me the steps in detail? Best,Rong
Avatar
Rong Jin March 18, 2024
Error 20227
I'm preparing model in  ls-dyna for seatbelt analysis. When I try to run a calculation, an error occures. Weird, because there are no beam elements with those id.Thanks for help.
Avatar
michal March 17, 2024
contact between two perpendicular shell plates
Hi, I am using shell elements for an I section and applying blast loading on its weak axis. I couldnt able to establish proper contact between flange and web. Any suggestions which contact is more suitable!  I tried merging nodes but couldnt achieve good results
Avatar
Jaswanth Gangolu March 17, 2024
Running more simulations at a time and extract results without manually opening
Hi, I need to automate running simulations and extracting results without manually opening each simulation. I'm using LS-DYNA to model blast loading on steel columns. Can someone provide a solution for this, preferably using MATLAB?
Avatar
Jaswanth Gangolu March 17, 2024
Ogden material models are used to show anomalies in LS-DYNA
Hello everyone, I got the stress-strain curve of uniaxial compression test of a foam, and used it to build its Ogden material model in the engineering database, as shown in the figure. I used the fitting function of ANSYS to get the parameters of the material formula. When I used it for Droptest emulation, the solver gave me an error and I couldn't figure out why. In addition, I found a rubber 1 material in the engineering database, but it can normally participate in calculation. I couldn't find the reason for my calculation failure. I hope you can help me if you are in the same situation as me, thank you 
Avatar
云川 王 March 16, 2024
How autodyn imports external energy deposition
Hello, I have a question about autodyn. I would like to ask you how autodyn imports external energy deposition. I built a copper cylinder, and then knew the energy deposition corresponding to each point in it. How can I introduce the energy deposition into the cylinder, and then calculate the density pressure after a certain time, etc. I tried to carry out secondary development of autodyn and found that the EXSIE module in the subroutine can import energy deposition, but it only has one input parameter. I don't know how to input it, so I would like to ask for advice. The picture shows the subroutine EXSIEThe picture shows the energy deposition I want to import. The first and second columns are the coordinates, and the third column is the corresponding energy deposition
Avatar
wei zhang March 14, 2024
*DATABASE_TRHIST activation
I want to use the database *DATABASE_TRACER, but the R13 and R14 manuals state, "The option *DATABASE_TRHIST must be active." I can't find how to make it active in the manuals. Can anyone shed light on this? 
Avatar
Sa-aadat Parker March 14, 2024
About the energy plot in LS-DYNA
Hello,I'm using the SPH method in LS-DYNA to simulate the high-speed impact problem (Using a metal ballistic projectile to impact a metal plate). I find that the internal energy is not consistent with different numbers of particles (different meshes) for the plate and the projectile. The results are listed below, which are the coarse mesh (70*70*19=93100 nodes), medium mesh (107*107*28=320572 nodes), and fine mesh (151*151*40=912040 nodes).All the other setups are kept the same for the three cases. As can be seen, the internal energy is not convergent for these cases. For example, the internal energy at 1e-5 s is 2.8e9 (coarse mesh), 3e9 (medium mesh), and 3.5e9 (fine mesh) respectively. These results are calculated by the R 13.0 solver. I also tried to use R 14.0 solver but the results still show a different trend. Even for some cases, the job will stuck at 33% or 46% and I don't know why.I would like to know how LS-DYNA calculates the internal energy and how I can verify it. We know that the internal energy can be divided into two parts. One is the strain energy, which can be calculated by particle strain and stress. The other is heat, which can be calculated by the particle temperature change. For strain energy, I plan to output all the stress and strain of all the particles in each timestep, then I can calculate the increment of strain δε, then time σ, and the total volume and sum, which is the internal energy. For the heat, I plan to output all the temperature change, then times the total mass and specific heat capacity, which is the total heat generated. However, in some cases, I find that the sum of total strain energy calculated and total heat calculated does not equal to the total internal energy directly plotted in *MATSUM. Best,Rong
Avatar
Rong Jin March 13, 2024
A question about the Stiffness Type in Coupling
Dear all,I am using LS-DYNA to simulate a bottle filled with water falling onto the ground. When setting up the Coupling, I chose "Tabular" for the Stiffness Type. Therefore, I need to input Displacement vs. Coupling Pressure. Can anyone tell me what the values (The displacement vs pressure) should be like for my simulation case? Best,Tomas
Avatar
Tomas Black March 13, 2024
Cylindrical Coordinate System
Can I please know how to provide the cylindrical coordinate system (rotation, theta and z) for providing BOUNDARY_SPC in LS DYNA?
Avatar
Thamanna Iqbal March 12, 2024
LS-OPT Error
Hello everyone,I'm a beginner in LS-OPT and I'm trying to practice on training examples. But every time I run a job, I get the same error message "No backtrace information avaible under windows". I've seen various solutions (no blank, or - in the main file...) on other forums, but none have helped. Do you have any idea what the problem is? I'm trying to identify a parameter with an LS-DYNA solver, something realy classic.Thanks 
Avatar
Pierre Gardère March 12, 2024
Mat 011 Steinberg Guinan translation to LS-DYNA keycard
Hello all, I posted previously about the Steinberg-Guinan model and implementing it in Workbench LS-DYNA as a keycard input. I have since attempted this but the formatting for the actual equation parameters is confusing, particularly the derivative terms. They are not well labeled in the LS-DYNA theory manual. Does anyone have an example material for Mat 011 in keycard format that I can compare to? Thank you!
Avatar
Alex Horwege March 12, 2024
SPH brittle modeling with UMAT
Greetings, dear colleagues. I want to perform the modeling of complex brittle failure of material with spalling. Could you please clarify the following points:1) I think about using the SPH method for this purpose but I heard that it is unstable for brittle crushing simulations. Is it true?2) Can I use my own material model (UMAT) with failure criterion for SPH simulations?3) Is it possible to define particle-to-particle contact between failed particles? I want to implement the case where crushed parts of model interact with each other after crushing. Thank you in advance.
Avatar
Oleg Makarov March 11, 2024
Write Input file Explicit Dynamic
Hello, how can i generate a Input file for a hpc server. I already tried to add a transient calculation to the explicit dynamics but it still doesn't work.Daniel
Avatar
Daniel Dabic March 11, 2024
About load setting
I want to use force to simulate a rotating object. How can I apply node forces in the normal direction of multiple nodes in ls-dyna?
Avatar
REX LIOU March 11, 2024
Connecting beam elements to solid elements
Hi,What is the best way to connect a beam element to a solid element in LS-prepost so that moments, shears and rotations are transfered at the interface? I am modelling a concrete pier that is connected to a concrete footing. The dynamic analysis is intended to remain within the linear elastic regime. I have modeled the pier with beam elements and the footing with brick (solid) elements. The pier is located at the center of the footing where there is no node at the top of the footing for direct connection, due to the mesh size and layout. I have tried using Constrained_Nodal_Rigid_Body to connect all the nodes at the top of the footing to the node at the bottom of the pier. The  results obtained were not realistic, thus, I am wondering if there is another way to make this connection in LS-prepost.Thanks
Avatar
king79 March 11, 2024
effetive stress vs strain curve not as expected
HiI used "MAT_PLASTIC_KINEMATIC model to model a pipe-tank simulation. The Mat card looks like below:I am applying 0.305 m displacement in +Y direction to represent sliding which looks like below: However, when I checked the effective stress at pipe-tank connection nodes, it seems they are not behaving as expected. I checked effective strain at a certain element which has maximum effective stress (at connection between tank and bottom), it looks like below: My yield stress was 450 MPa and E = 200 GPa. My yield strain is 0.092. So, @0.092 the stress should be 450 MPa, right? Do you know, why the stress-strain does not look okay? To let you know, I was applying prescribed motion by selecting all bottom nodes of tank in Y direction. But in other case, when I apply prescribed motion in Z direction to represent flotation of tank, I get expected results which looks below:
Avatar
mmia1@lsu.edu March 9, 2024
Deflections not matching for simple cantilever beam check
Hello,I am looking to use *ELEMENT_SHELL_COMPOSITE for tow-steered composite modeling and ran a simple cantilever beam test to see if the element type was working as expected.  For my test case, the material is steel (E = 200 GPa), the dimensions are L = 100 mm, w = 10 mm, and h = 3 mm, and a 50 N load is applied the the nodes at the end.  Solving by hand, I expect to get a deflection of about 3.7 mm.  I modeled the problem using *ELEMENT_SHELL and got 3.67 mm.  With the working model, I transfered the elements from *ELEMENT_SHELL to *ELEMENT_SHELL_COMPOSITE and modeled it with 3 "steel plies" each 1 mm thick.  The transfer was done by using EleTol->ElmEdit->Composite, inserting 3 plies, and assigning the material and thickness (I did not touch the direction).  Running this gave a deflection of 4.13 mm.  Any idea how to fix the *ELEMENT_SHELL_COMPOSITE model?  I did try LAMSHT=1 in *CONTROL_SHELL, but the deflection did not change.
Avatar
Eli Bogetti March 8, 2024
error 3 in em_eleTypeToFemMapGlobBath1
I encountered an error while running the battery extrusion simulation, but I can't figure out where the problem is.May I ask where exactly this error occurred?
Avatar
LIN JUN HONG March 7, 2024
LS DYNA Tools
For my project, I need to providing stitching upon overlapped membrane parts (similarly like stitching of fabric material). Can I please know how to simulate this in LS DYNA?
Avatar
Thamanna Iqbal March 6, 2024
Calculating contact stiffness
Hello,I'm currently working on a thesis project and I'm trying to approximate a contact stiffness in order to compare the results of my simulation to those from a self written MATLAB routine in which I specify a contact stiffness as a concrete value. I'm using shells and what I can find is k = alpha*K*A / (max shell diagonal) where k is the contact stiffness, alpha is a penalty scale factor, K is the bulk modulus and A is the segment area.Assuming this is the right way to calculate it and provided I use a mesh with equally sized elements (that is, I know the max shell diagonal), how do I find alpha and A? The contact I'm looking at is a turbine blade edge coming into contact with the surrounding stator wall surface.Thanks in advance for the help.
Avatar
Henrik Wittberg March 6, 2024
Do I need to set both surface contact and body interaction in workbench LS-DYNA?
Dear all,If we have already set the surface bonded contact between two parts, do I still need to set the solid interaction between them? I find that whether or not the solid interaction is set, the results obtained from the calculations can be different.Thanks,Tomas
Avatar
Tomas Black March 6, 2024
error in function SPvec_initSparse,
Hello,I'm having a problem while using the EM solver in LS Dyna.            error from spvec_initsparse(spvObject)  -2            error from spvec_initsparse(spvObject)  -2            error from spvec_initsparse(spvObject)  -2(error in function SPvec_initSparse, at line 158, in file ../..//spooles.v6/SPvec/src/init.c) this is exact error.Using R13 MPP double precision.Please help me.Regards
Avatar
GongCheng Peng March 6, 2024
Need some help in *BOUNDARY_PRESCRIBED_MOTION_SPC
Hi I have some confuison in *BOUNDARY_PRESCRIBED_MOTION_SPC. I am applying displacement as prescribed motion at all nodes at bottom plate of a tank in Y direction. I then applied *BOUNDARY_SPC restricting the movements in X and Z and rotations in all three directions. The card looks like below:     I found some online resources which states, "you shouldn't need both *Boundary_prescribed_motion and *Boundary_spc. You should just be able to create a node set and use *boundary_prescribed_motion_set where you will reference the node set and use your current settings. The DOF in the boundary prescribed motion card will restrict motion to only that direction so you don't need spc."  But when i don't use *Boundary_spc then the model got aborted. However, if I use *Boundary_spc restricting the movement in other two directions (X and Z including rotations in all three directions), then the model works fine.  Please provide me some insights on this. Thanks again. Regards,
Avatar
mmia1@lsu.edu March 5, 2024

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